LFX experiencing run-on every now and then - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

ChibiBlackSheep · 02-22-2018, 12:41 PM

Anyone else having any issues with the engine staying running while the car is shut off? Trying to track this down on my LFX.

It isn't happening all of the time, but some nights when I park in my driveway, I'll have the car in 1st, clutch pressed in, apply the parking brake, turn the engine off, remove the key from the ignition, and it's still sputtering and running. If I clutch out the car stalls, and if I keep holding the clutch in, it eventually sputters out and dies.

sixty9fordkiller · 02-22-2018, 02:06 PM

try changing gas brand/octane first and see what she does before starting anything else

ChibiBlackSheep · 02-22-2018, 02:09 PM

I'm tuned with 93 octane sunoco in the car, and only ever use 93 Sunoco.

sixty9fordkiller · 02-22-2018, 02:11 PM

have you made any changes lately before it started? spark plugs? CAI? exhaust? fuel system cleaner?

ChibiBlackSheep · 02-22-2018, 02:24 PM

Quote:

Originally Posted by sixty9fordkiller

have you made any changes lately before it started? spark plugs? CAI? exhaust? fuel system cleaner?

Negative. Have had no changes made recently. It's done this once before for 2 days (roughly 2 months ago), and then went away. Last night it did it again.

Last time this happened, I checked all of the sensors, and cleaned the MAF. This weekend I'll pull a plug or 2 and take a look at those.

Just curious if anyone else has experienced this with the LFX before.

Other notes, oil level is good, car has a catch-can and has had it for its whole life, 62,000 miles.

sixty9fordkiller · 02-22-2018, 02:29 PM

i would start by changing gas stations and checking for vacuum leaks and pulling the spark plugs to see what they look like. Wont cost you a dime and only about an hour of your time

acammer · 02-22-2018, 02:48 PM

A fuel injected car with run on? I can't say I've heard of that. Must be burning oil, because it should quit delivering fuel the second you turn the key off. Maybe it's indicative of an injector that doesn't close all the way or something. I've never heard of anything like that - I'd be interested to learn what you find.

ChibiBlackSheep · 02-22-2018, 03:00 PM

Quote:

Originally Posted by acammer

A fuel injected car with run on? I can't say I've heard of that. Must be burning oil, because it should quit delivering fuel the second you turn the key off. Maybe it's indicative of an injector that doesn't close all the way or something. I've never heard of anything like that - I'd be interested to learn what you find.

I know, it blew my mind the first time it happened. I was holding the key in my hand, and stalled my car.

DSX_Camaro · 02-22-2018, 08:38 PM

Uh. Well. Do you have an OBD2 module? You might have a code to go off of even if the CEL isn't on. That, or if you had some way of looking at the car's data while it's running / shutting off that would help a lot. Like acammer said, sounds like a fuel issue, injector or otherwise. Also sounds like the inverse of an issue I had a few months ago where I started my car and it started sputtering almost immediately and threw a TPS / MAF correlation error CEL. It actually did that a total of 3 times over like 30 days. Hasn't done it since though.

xstuntman · 02-22-2018, 08:41 PM

Leaking injectors can give you the dieseling experience. Rare but it's happened.

ChibiBlackSheep · 02-23-2018, 01:21 PM

I do have HPTuners and can run scans. Naturally it hasn't done it since I started this thread and hooked my HPT to it.

gringo · 02-24-2018, 02:12 AM

Check the fuel pressure regulator.

sixty9fordkiller · 02-24-2018, 09:16 AM

the V6 cars have a fuel pressure regulator?

blackswan · 02-24-2018, 12:08 PM

Bad ignition switch? If the switch is good than something is igniting the fuel, likely carbon deposits. Suggest getting a boroscope and pulling each plug and taking a look inside. But, yes like someone else said, this shouldn't happen with fuel injected vehicles since the fuel supply should be cut off with the ignition switch. If fuel is leaking from injectors, then that could be part of this as well. Perhaps let it sit overnight and then pull each plug and see if you smell gas more than others, which might be a leaking injector.

02-22-2018, 12:41 PM	#1
ChibiBlackSheep Drives: 2012 2SS/RS, 1968 SS Join Date: Feb 2012 Location: Southeast, PA Posts: 2,085	LFX experiencing run-on every now and then Anyone else having any issues with the engine staying running while the car is shut off? Trying to track this down on my LFX. It isn't happening all of the time, but some nights when I park in my driveway, I'll have the car in 1st, clutch pressed in, apply the parking brake, turn the engine off, remove the key from the ignition, and it's still sputtering and running. If I clutch out the car stalls, and if I keep holding the clutch in, it eventually sputters out and dies. __________________ LS3 Crate Engine Swap \| CSP Custom Cam 232/240 .615/.615 113 +3 \| Stainless Power LT Headers \| Z28 Intake \| Borla S-Type Exhaust \| FTI Triple-Disc Billet 3200 Stall 2012 Camaro 2SS/RS \| 1968 Camaro SS \| 2020 Cadillac CT5 Premium Luxury \| 2021 Spark LS

02-22-2018, 02:06 PM	#2
sixty9fordkiller Donkey Dick Cam Camaro Drives: 2010 2SS/RS LS3 M6 Join Date: Oct 2009 Location: Los Angeles, CA Posts: 2,000	try changing gas brand/octane first and see what she does before starting anything else __________________ Bone Stock

02-22-2018, 02:09 PM	#3
ChibiBlackSheep Drives: 2012 2SS/RS, 1968 SS Join Date: Feb 2012 Location: Southeast, PA Posts: 2,085	I'm tuned with 93 octane sunoco in the car, and only ever use 93 Sunoco. __________________ LS3 Crate Engine Swap \| CSP Custom Cam 232/240 .615/.615 113 +3 \| Stainless Power LT Headers \| Z28 Intake \| Borla S-Type Exhaust \| FTI Triple-Disc Billet 3200 Stall 2012 Camaro 2SS/RS \| 1968 Camaro SS \| 2020 Cadillac CT5 Premium Luxury \| 2021 Spark LS

02-22-2018, 02:11 PM	#4
sixty9fordkiller Donkey Dick Cam Camaro Drives: 2010 2SS/RS LS3 M6 Join Date: Oct 2009 Location: Los Angeles, CA Posts: 2,000	have you made any changes lately before it started? spark plugs? CAI? exhaust? fuel system cleaner? __________________ Bone Stock

02-22-2018, 02:29 PM	#6
sixty9fordkiller Donkey Dick Cam Camaro Drives: 2010 2SS/RS LS3 M6 Join Date: Oct 2009 Location: Los Angeles, CA Posts: 2,000	i would start by changing gas stations and checking for vacuum leaks and pulling the spark plugs to see what they look like. Wont cost you a dime and only about an hour of your time __________________ Bone Stock

02-22-2018, 02:48 PM	#7
acammer GPI Sales Consultant Drives: 2011 Camaro 2SS SGM Join Date: Jul 2016 Location: Weedsport, NY Posts: 2,794 View My Garage	A fuel injected car with run on? I can't say I've heard of that. Must be burning oil, because it should quit delivering fuel the second you turn the key off. Maybe it's indicative of an injector that doesn't close all the way or something. I've never heard of anything like that - I'd be interested to learn what you find. __________________ GPI Max Package 2.0: Brodix BR7 heads/GPI porting, MAX3 cam, ST2116LSR, BSR Max Lift rockers, LS7 LSXR with 103mm TB, Vararam OTR, Mcleod RXT, G-Force/Strange 9" IRS setup with 4.63 gear. 551whp, 11.1@124mph. *Got a question about a GPI product? Feel free to shoot me a message!*

02-22-2018, 08:38 PM	#9
DSX_Camaro Drives: 2013 SW 2LT/RS LFX/AY6 Join Date: Feb 2013 Location: Orlando, FL Posts: 1,741	Uh. Well. Do you have an OBD2 module? You might have a code to go off of even if the CEL isn't on. That, or if you had some way of looking at the car's data while it's running / shutting off that would help a lot. Like acammer said, sounds like a fuel issue, injector or otherwise. Also sounds like the inverse of an issue I had a few months ago where I started my car and it started sputtering almost immediately and threw a TPS / MAF correlation error CEL. It actually did that a total of 3 times over like 30 days. Hasn't done it since though. __________________ K&N CAI, 1LE Strut Tower Brace, Elite Engineering Catch Can and Clean Side Separator, Apex Scoop w/ Washer Relocation Kit, CTS Front Calipers and Rotors, JacFab Ported Intake Manifold, JacFab Intake Manifold Spacer, 80mm Overkill Throttle Body, SS Brake Lines, Ideal Garage Master Cylinder, Monster Twin Disc Clutch, NPP Retrofit w/ Magnaflow Resonated X, ARH Catless Downpipes, JRE Built 3.45 Diff, 1LE Axles, 1LE Hubs, Overkill Tuned, BMR Anti Wheel-hop Kit Stage I, ACS TL1 Hood Insert, ZL1 Spoiler

02-22-2018, 08:41 PM	#10
xstuntman Drives: 2012 Victory Red LFX Join Date: Dec 2012 Location: west central Texas Posts: 1,310	Leaking injectors can give you the dieseling experience. Rare but it's happened. __________________ 2018 SS wheels, red Heritage grille, actual driving lights, ZL1 strut tower brace, GM Performance billet aluminum fuel door, front grille Bowtie delete, painted red rotors and calipers, 1/4 window American Flags, splash guards, AEM dry panel air filter.

02-23-2018, 01:21 PM	#11
ChibiBlackSheep Drives: 2012 2SS/RS, 1968 SS Join Date: Feb 2012 Location: Southeast, PA Posts: 2,085	I do have HPTuners and can run scans. Naturally it hasn't done it since I started this thread and hooked my HPT to it. __________________ LS3 Crate Engine Swap \| CSP Custom Cam 232/240 .615/.615 113 +3 \| Stainless Power LT Headers \| Z28 Intake \| Borla S-Type Exhaust \| FTI Triple-Disc Billet 3200 Stall 2012 Camaro 2SS/RS \| 1968 Camaro SS \| 2020 Cadillac CT5 Premium Luxury \| 2021 Spark LS

02-24-2018, 02:12 AM	#12
gringo Account Suspended Drives: Camaro V6 Join Date: Oct 2016 Location: U.S. Posts: 1,722	Check the fuel pressure regulator.

02-24-2018, 09:16 AM	#13
sixty9fordkiller Donkey Dick Cam Camaro Drives: 2010 2SS/RS LS3 M6 Join Date: Oct 2009 Location: Los Angeles, CA Posts: 2,000	the V6 cars have a fuel pressure regulator? __________________ Bone Stock

02-24-2018, 12:08 PM	#14
blackswan Drives: 2012 2LT/RS Join Date: Oct 2011 Location: Northeast Posts: 1,443	Bad ignition switch? If the switch is good than something is igniting the fuel, likely carbon deposits. Suggest getting a boroscope and pulling each plug and taking a look inside. But, yes like someone else said, this shouldn't happen with fuel injected vehicles since the fuel supply should be cut off with the ignition switch. If fuel is leaking from injectors, then that could be part of this as well. Perhaps let it sit overnight and then pull each plug and see if you smell gas more than others, which might be a leaking injector.